Кошка залетела в квартиру: что делать? Беременная кошка на 3 этаже

So I left my sliding door cracked for my cat to be able to come in and out. I come home and there’s this rando ass cat in my apartment. Turned out it’s a she and she’s pregnant🥲

I’ve never seen her as a stray here so I think she might belong to someone. She looks quite healthy . She won’t leave my patio .

Mind you I’m on the 3rd floor…